公开(公告)号：US2925462A

公开(公告)日：1960-02-16

申请号：US48480255

申请日：1955-01-28

Applicant: RCA CORP

Inventor： PRITCHARD DALTON H ,  SCHROEDER ALFRED C ,  GIBSON WALTER G

IPC: H04N9/66

CPC classification number: H04N9/66

公开(公告)号：US2743310A

公开(公告)日：1956-04-24

申请号：US39796053

申请日：1953-12-14

Applicant: RCA CORP

Inventor： SCHROEDER ALFRED C ,  GIBSON WALTER G

IPC: H04N11/14

CPC classification number: H04N11/143

公开(公告)号：CA1142642A

公开(公告)日：1983-03-08

申请号：CA363231

申请日：1980-10-24

Applicant: RCA CORP

Inventor： GIBSON WALTER G

IPC: H04N5/14 ,  H03H7/01 ,  H03H7/46 ,  H04N5/60 ,  H04N5/62 ,  H04N7/18

Abstract: RCA 73,977 A signal separation network is provided which accomplishes the functions of a sound take-off network and intercarrier sound trap in a single network. A common detector produces detected composite video and inter carrier sound signals. Circuitry is provided for processing the composite video signal, and a separate circuit is provided for processing sound information. The signal separation network has an input responsive to the detected composite video and intercarrier sound signals, a first output terminal coupled to the input of the video processing circuitry, and a second output terminal coupled to the input of the sound processing circuitry. The network is characterized by a transfer function which exhibits a dominant zero approximately at the intercarrier sound frequency at the first output terminal, which provides trapping of the intercarrier sound signal in the path to the video processing circuitry. The network is also characterized by a transfer function at the second output terminal which exhibits a dominant pole substantially at the intercarrier sound frequency and a zero at a lower frequency so as to peak the response at the second terminal around the intercarrier sound frequency. The intercarrier sound signal is therefore prefiltered by the bandpass characteristic at this second terminal and is then applied to the sound processing circuitry. The network may be arranged in either a series tuned or a bridged-T configuration, and may also be arranged so as to exhibit a zero in the transfer function at the second output terminal which provides attenuation of mid-band video signals in the sound channel.

公开(公告)号：CA1295698C

公开(公告)日：1992-02-11

申请号：CA550742

申请日：1987-10-30

Applicant: RCA CORP

Inventor： DOTY JAMES H II ,  GIBSON WALTER G

IPC: H03B5/06 ,  H03B5/12 ,  H03K3/80 ,  H03L7/24

Abstract: An amplifier having a resonator coupled between input and output terminals thereof supplies a dot clock signal to a character generator in a television receiver. A feedback control circuit supplies DC bias to the resonator during blanking intervals that preceed lines of characters to be displayed to ensure a consistent starting phase for oscillations, removes the DC bias and supplies operating power to the amplifier during a portion of the active video period of each displayed line for sustaining the oscillations and automatically inhibits the supply of amplifier power at the end of each active line of characters to thereby provide three oscillator operating modes of PRIMED, RUNNING and OFF so as to minimize overall power consumption for the oscillator for each field of displayed characters.

公开(公告)号：PL219324A1

公开(公告)日：1980-08-11

申请号：PL21932479

申请日：1979-10-30

Applicant: RCA CORP

Inventor： LIN FRANK CH ,  GIBSON WALTER G

IPC: H03D3/26 ,  H03J7/02 ,  H03J7/04 ,  H03L7/02 ,  H03B

Abstract: An automatic fine tuning (AFT) circuit is provided which generates an AFT control signal in response to a video intermedate frequency (I.F.) signal. The I.F. signal is supplied to the input of a current source amplifier, which provides current signals of like phase relationship to a discriminator network. The discriminator network is comprised of two tuned circuits, one of which is resonant at a frequency below the desired frequency of the I.F. picture carrier, and the other resonant at a frequency above the desired frequency. The tuned circuits develop voltage variations which vary differentially in magnitude in response to the frequency deviation of the I.F. picture carrier from its desired frequency. The differentially related voltages are detected by two peak detector networks for use as AFT control signals. The current source amplifier and peak detector networks may be conveniently fabricated on a single I.C. chip. The tuned circuits are coupled to the current source amplifier and peak detector networks through two external I.C. terminals.

公开(公告)号：CA685570A

公开(公告)日：1964-04-28

申请号：CA685570D

Applicant: RCA CORP

Inventor： GIBSON WALTER G ,  SCHROEDER ALFRED C

公开(公告)号：CA1147453A

公开(公告)日：1983-05-31

申请号：CA358607

申请日：1980-08-19

Applicant: RCA CORP

Inventor： GIBSON WALTER G ,  LIU FRANK C ,  MUTERSPAUGH MAX W

IPC: H04N5/455 ,  H04N5/20 ,  H04N5/50 ,  H04N5/44

Abstract: RCA 74,057 A selectivity network is provided for a synchronous detector, a reference signal circuit, and an AFT circuit. The selectivity network comprises a first tuned circuit coupled across two terminals of the reference signal circuit and tuned to the desired frequency of the I.F. picture carrier. A second tuned circuit is lightly coupled to the first tuned circuit and is coupled across two inputs of the AFT circuit to provide a frequency dependent phase-shifted reference signal to the AFT circuit. The first tuned circuit includes a trap circuit tuned to provide attenuation about a frequency intermediate the frequency of a sound carrier and that picture signal sideband frequency which, upon detection, results in a video signal corresponding to the intercarrier sound second subharmonic frequency. The trap in the reference signal tuned circuit minimizes quadrature distortion in the reference channel and the resultant harmonic distortion in the video signals, which causes sound buzz. The frequency notched reference signal is applied to the AFT tuned circuit, which causes a balancing of the pull-in range of the AFT circuit about the desired picture carrier frequency, thereby immunizing the AFT circuit against noise-pulling. The frequency notch in the AFT circuit at the indicated frequency also minimizes AFT effects of a frequency offset co-channel sound carrier, allowing the automatic acquisition of signals which are offset in frequency toward the lower adjacent channel.

公开(公告)号：CA1135403A

公开(公告)日：1982-11-09

申请号：CA338670

申请日：1979-10-29

Applicant: RCA CORP

Inventor： GIBSON WALTER G ,  LIU FRANK C-S

IPC: H03J7/02 ,  H03D3/26 ,  H03J7/04 ,  H03L7/02 ,  H03D9/00

Abstract: RCA 72,428 An automatic fine tuning (AFT) circuit is provided which generates an AFT control signal in response to a video intermediate frequency (I.F.) signal. The I.F. signal is supplied to the input of a current source amplifier, which provides current signals of like phase relationship to a discriminator network. The discriminator network is comprised of two tuned circuits, one of which is resonant at a frequency below the desired frequency of the I.F. picture carrier, and the other resonant at a frequency above the desired frequency. The tuned circuits develop voltage variations which vary differentially in magnitude in response to the frequency deviation of the I.F. picture carrier from its desired frequency. The differentially related voltages are detected by two peak detector networks for use as AFT control signals. The current source amplifier and peak detector networks may be conveniently fabricated on a single I.C. chip. The tuned circuits are coupled to the current source amplifier and peak detector networks through two external I.C. terminals. `

公开(公告)号：CA839430A

公开(公告)日：1970-04-14

申请号：CA839430D

Applicant: RCA CORP

Inventor： GIBSON WALTER G ,  GRAVEL ARTHUR J